A sensitive H 2 S sensor using MoS 2 /WO 3 composite

Present work demonstrates the synthesis of MoS 2 /WO 3 composite using a facile two step method. In first step WO 3 was obtained using precipitation method. In the second step, WO 3 was probe sonicated and following hydrothermal approach MoS 2 /WO 3 hybrid was obtained. The finally obtained black powder was used for structural as well as gas sensing purpose. The structural analysis using high resolution trans- mission electron microscopy revealed the presence of various planes corresponding to WO 3 and MoS 2 . The images also revealed the presence of various defects. These defects might be beneficial for gas adsorption and may enhance the sensitivity of the composite. The Raman spectra revealed various Raman active modes corresponding to bending and stretching of O -W -O bonds. Spectra also displayed first order (A 1g and E 12g ) Raman active modes belonging to MoS 2 , indicating successful formation of hybrid. A relative response of nearly 20% was obtained at 350 ?C for 25 ppm of H 2 S and device was found to be more selective towards H 2 S than methanol, ethanol and acetone and showed n -type semiconducting properties. ? 2019 Elsevier Ltd. All rights reserved. Selection and Peer -review under responsibility of the scientific committee of the International Confer- ence on Advanced Materials and Nanotechnology.